(1) Field of Invention
The present invention is concerned with the utilization of white sweet potatoes and all other light-fleshed tubers of the family Convolvulaceae, with the purpose of producing various flours from the tubers, and other valuable edible products and industrial products. Similarly, the present invention is concerned with producing flours and other valuable edible and industrial products from: 1) the tubers of the cassava and all other plants producing tubers of the family Euphorbiaceae; 2) tubers of malanga and all other plants producing tubers of the family Araceae; 3) the seeds of the amaranth, quinoa and all other seeds from the families Chenopodiaceae and Amaranthaceae, 4) the tubers of the yam and all plants producing tubers in the family Dioscoreaceae; and 5) the tubers of the lotus, arrowhead, buckbean and all other plants producing tubers in the families Nymphaeaceae, Alismataceae, and Gentianaceae.
(2) Description of The Background
Having food products available from as many different food sources as possible is of the greatest importance to persons with food allergies, and will become of even greater importance as food allergies are diagnosed in increasing numbers of people. As the potential problems of food allergies are more recognized, increasing numbers of people are looking for non-wheat items to include in their diets, to increase variety and aid in the prevention of food allergies.
Food allergies and intolerances have been known to exist for hundreds of years. The symptoms vary with each individual, and can include congestion, asthma, diarrhea, headaches, dizziness, joint pains, hives, eczema and in the most severe cases can cause anaphylaxis and even death. In recent decades, along with most other diseases related to the immune or auto-immune system, the incidence of food allergies has increased. In addition the number of foods to which a given individual reacts, and the severity of the reactions seems to be increasing. Indications are that food allergies will continue to become increasingly more common and severe.
The need for new food sources and alternatives parallels the increase in food allergies. As the number of foods an individual can eat begins to dwindle, it becomes increasingly more difficult to maintain a nutritious, well-balanced diet from the foods remaining, and the search for new foods intensifies. For many food allergy patients, the allergy problem steadily becomes more severe as the patient is unable to avoid becoming malnourished.
There is, then, a real need for alternatives to the food products that are the common and accepted staples in the American diet. These food products need to be from hypoallergenic foods so they have the best chance of being well tolerated by the greatest numbers of people. The hypoallergenic food products need to provide acceptable substitutes for the most hyperallergenic food products--wheat, corn, and other members of the grass family, legumes, milk and milk products, eggs, nuts, and yeast.
The alternative food products should be from less common or less well known foods. Such foods will have been eaten less often, if at all, and there will be a lower chance for a person to have developed allergies to the new foods. Products from such uncommon foods could probably be tolerated by most persons, and the risk of developing allergies to the foods would be lower.
The alternative food products need to be developed from foods in separate food families. This is important because food allergy patients can easily develop allergies to foods that are closely related to the foods they are already allergic to. New food products from as many new food families as possible (for example white sweet potato products from the morning glory family, cassava products from the spurge family, yam products from family Dioscoreaceae, and lotus from the water lily family), are much more needed than are food products from uncommon foods in a common food family (such as millet from the grass family). Alternative food products from food families not frequently included in peoples' diets will increase substantially the foods that people can eat in their rotation diets.
The alternative food products need to be highly concentrated foods. The above list of hyperallergenic foods includes most of the concentrated carbohydrates in the normal American diet. When people have to exclude these foods from their diets, the plant sources they have left to eat are primarily green leafy vegetables, tubers, and fruits. These food sources are high in fiber, but are relatively low in carbohydrates. A person who must rely on potatoes or sweet potatoes as their main source of carbohydrates, must eat about 5 pounds each day. It is very hard for many adults to eat this much food, but it is even more difficult for allergic children who may have to eat almost as much as an adult.
The alternative food products need to be as close to the eliminated foods as possible, in form and texture. For example, breads, pastas, cereal, cookies are needed from hypoallergenic sources, and these need to be as similar in taste and texture to their hyperallergenic counterparts as possible. This will make it possible for persons to enjoy foods they are used to, and will make them more likely to stay on their diets. Also people who are concerned that they may have food allergies are more likely to seek medical treatment if they know they will have pleasant alternatives in their diets.
Alternative food products are needed that consist of one primary ingredient, and this ingredient serves to replace wheat and other grains, milk, eggs, nuts, yeast, and sugar. The food allergies of individuals vary so greatly, that as the number of ingredients in a product increases, the number of individuals that can use the product decreases. Similarly, the products need to be free of additives, preservatives, and so forth, and should be completely free of pesticides and other chemicals.
Other characteristics that are important in new food products include convenience, portability, and variety. Many patients must change their diets at a time when they are very ill, and they simply do not have the strength to perform the food preparation needed when working with fresh fruits and vegetables.
Until now there has been no food product which could meet all of the above criteria. Many food products have been developed, but essentially all contain either wheat, or other grains, soy or legumes, milk, eggs, nuts, yeast, or sugar, or they do not have the characteristics of the common food products. Many specialty flours such as amaranth, have been combined with wheat flour to make new products, and these are not useful to the food allergic patient. Until now, it has not heretofore been possible to completely replace wheat products with a non-grain flour that also does not contain other main ingredients such as legumes, eggs, milk, sugar, and yeast, and also chemical modifiers.
In order to develop the needed alternative food products, it was first necessary to identify flours with suitable properties, and further with each of such flours, separately, as primary ingredient, to develop processes and techniques for preparing food products with properties and characteristics previously obtainable only from products containing wheat and other grains, legumes, eggs, milk, nuts and the like.
To find flours with suitable properties, existing flours of the art for sweet potatoes, cassava, malanga, yam, amaranth, quinoa, lotus, arrowhead, and buckthorn were evaluated. As is described below, using these art flours, other investigators had previously attempted to develop food products that were as completely non-grain in content as possible. In no case were these investigators able to prepare the desired food products without including other ingredients such as chemical modifiers, grain flours, high protein flours, eggs, milk, and the like. In most cases, prior investigators were able to use a non-wheat flour as a substitute for only a small percentage of the total amount of wheat flour in baked products. Uses of high carbohydrate flours to prepare substitutes for milk and milk products, eggs, and nuts is unknown.
Therefore it was necessary to develop new flours which could be more successfully used in the preparation of non-wheat flour products. Contrary to the teachings of the art, the applicant has found that when the dried tubers or seeds were comminuted to fine, relatively uniform particle size and wherein said relatively uniform particle size is obtained with greatly reduced amounts of sifting or without sifting, and thereby containing most or all of the plant fiber and other non-farinaceous material of the tuber or seed in the finely divided flour, there resulted a flour with unique and suprising properties, which was suitable for developing the desired processes and products.
These flours were found to each have unique and suprisingly different properties, and methods of preparation of each flour differ as well. Although no flour could be used in the same way as wheat flour, and although no two flours could be used in the same ways. It was possible to develop processes for each flour, and these processes were used to produce products comprising substantially one non-wheat flour ingredient with such products having properties and characteristics previously obtainable only from products containing ingredients selected from: wheat and other grains, legumes, eggs, milk, nuts, chemical modifiers, and the like.
New flour products with heretofore unobtainable properties have been developed from tubers of white or light fleshed sweet potatoes, cassava. malanga, tropical yams, lotus, arrowhead, and buckbean, and seeds of amaranth and quinoa. Each flour possesses different, unique, and suprising properties. Separate processes have been developed for each flour that allow its use as a substitute for grains, milk, and eggs, among other uses.
White sweet potatoes: The properties of flour and starch prepared from orange sweet potatoes are well known, and have been reported in the patent literature as early as the 1840's. Dried, ground orange sweet potatoes were patented for use as an ingredient in a coffee blend (U.S. Pat. No. 100,587 issued in 1870) because dried orange sweet potatoes look and taste like burned bricks. The caroteen pigment concentrates during drying and causes the disagreeable taste and color. The other patented uses of orange sweet potato flour are limited primarily to that of rehydratable powders primarily for use in orange sweet potato pie or pumpkin pies. This is probably due to the strong taste of orange sweet potato flour, the fact that when rehydrated, orange sweet potato flour loses cohesion, and will not keep a shape or hold trapped air. There are numerous mentions in the patent literature of processes for combining cooked or raw starches or flours from starchy tubers with various ingredients. Sweet potatoes (orange varieties) are frequently used as examples of `other tubers`.
There is no reference to flours of white sweet potato varieties in the U.S. patent literature.
Several important teachings of the art have directed investigators completely away from any consideration of white sweet potatoes as possibilities for producing useful products.
Raw orange sweet potato flour made by the methods of Marshall (U.S. Pat. No. 77,995), and Baylor (U.S. Pat. No. 100,587) produced a flour considered inferior. The orange sweet potatoes tended to darken during dehydration; this darkened flour could not be rehydrated to make a good tasting substitute for the original fresh product, and the flour tended to have a very strong bitter taste, particularly when produced by the method of Baylor. Because of the inferior properties of raw orange sweet potato flour, in the late 1800's and early 1900's the field as a whole turned emphasis away from raw to cooked orange sweet potato flours. In the only mention of raw orange sweet potato flour since then, it is described as cattle fodder.
No orange sweet potato flour, whether raw or cooked, has been able to be used for more than about 30% of a wheat dough without significant deterioration in texture, risen structure, and taste. Even when a 15-85 mixture of orange sweet potato flour and wheat flour was used, the resulting bread product was significantly lower in specific volume. At ratios of 20-80, the specific volume of the bread product was reduced by 50 percent.
Other investigators have added cooked orange sweet potato flour to many products such as cookies, cakes, candies, ice cream, breads, and the like. In not one case was it possible to develop a product with orange sweet potato flour as the primary ingredient. It was only possible to add small amounts of cooked orange sweet potato flour to existing recipes containing conventional ingredients and to produce previously known products having orange sweet potato flavor and color.
White sweet potato flour is essentially an uninvestigated flour because fresh white sweet potatoes are considered (especially in the US) to be inferior to orange sweet potatoes. Sweet potatoes having white or light colored flesh are described as having poor quality and as being useful primarily for cattle fodder. If considered, the properties of white sweet potato flour would be expected to be less desirable than those of orange sweet potatoes. There would be no reason to suspect that a flour of white sweet potatoes could be prepared with properties greatly superior to flours of orange sweet potatoes. Thus the art teaches away from investigations on uses of white sweet potato flour.
In my early research on sweet potatoes, I tried making and using flours of orange sweet potatoes. The flavor of the raw orange sweet potato flour was very strong, as was described by other investigators. When I tried to use the flour to prepare pancakes and the like, the products fell apart in much the same way that fresh orange sweet potatoes tend to fall apart when they are cooked. In agreement with the teachings of the art, I was unable to prepare any products from orange sweet potato flour alone.
I then began to work with white sweet potatoes. In my early research on white sweet potato flour, the white sweet potato flour was made by a high speed impact method which produced a flour of wide particle-size distribution, with the fibrous portions of the tuber remaining in the larger particle sizes, and rendering the flour unsuitably heavy and gritty. When screened, (as is accepted practice in the art to obtain a fine flour) the larger particles (representing about 1/3 of the total weight of the comminuted meal) were removed; this produced a lighter and less gritty flour, but one poorly suited for producing breads and other products where consistency and lightness are important. In addition it has been found that previous shreds had a high moisture content that made them susceptible to spoilage during dehydration and produced inferior products that spoiled easily.
I then developed a new process for preparing white sweet potato flour which involved reducing moisture content, incorporating more fibrous and non-farinaceous material into the flour and obtaining a more uniform particle size distribution in the flour. This flour had improved storage capability and provided products of palatable consistency. This flour, the flour of the instantly claimed invention, is suitable for use in baked and other products, and it was possible to develop new processes, different from conventions of the art, which made it possible to use the white sweet potato flour of the instantly claimed invention to prepare products with properties and characteristics previously only obtainable from products containing wheat and other grains, legumes, eggs, milk, nuts and the like.
Cassava: Cassava is a tuberous root of the Spurge family, Euphorbiaceae. As a fresh tuber it is boiled in salted water and consumed directly or after further frying or baking. It is used in soups stews, and the like, or it is mashed to a thick paste and fried. A variety of dried pulverized products are known including: a mash is fermented then dried to form a coarse, crunchy meal; the fibers are separated from the starch which is dried and powdered. The cassava starch, also called cassava flour, is similar in properties to cornstarch. It has quite high expansion capabilities when mixed with water and gelatinized, and is therefore used as a thickener, an agent to increase the rise of many products, and an agent to improve consistency and homogenicity. Their are many references to cassava starch or tapioca starch in the literature, and some references to cassava flour called tapioca flour. By their interchanging uses it is apparent that such uses generally refer to the starch product and not to the flour.
Prior to the instantly claimed invention, four flours of cassava were known. None of these flours have the properties of the instantly claimed invention; none can be used in the ways described for the instantly claimed invention. The two most common cassava flours are formed from cassava starch extraction processes: the starch and the extracted fiber mat. The third flour is a composite flour, i.e., a mixture of cassava flour and a high protein flour. The fourth flour is a whole flour of cassava.
Cassava starch also called cassava flour, tapioca starch, and tapioca flour, is an extract of starch from cassava pulp, that is dried and pulverized to a flour. Most literature references to cassava or tapioca flour are references to cassava starch. Cassava starch has been used as a substitute for up to 30% of the wheat flour content in wheat-based bread-type products, but it is not possible to substitute cassava starch for more than 30% of wheat in wheat-based baking products.
Cassava meal is a highly fibrous (often fermented) meal prepared from the dried pulp fiber by-product of cassava starch production. The particles of the meal are about 1/2-1 mm in diameter. Gari, farinha, or mandioca are similar products of this type. Cassava meal is mixed with water and fried to produce a product called cassava bread. The bread is very hard and about 1/4 inch thick. It exhibits no risen structure and is simply a hard mat of fibers. Other uses of the meal include mixing the meal with meats and gravies, preparation of a gruel, and sprinkling the meal over food.
Composite flours of cassava are combinations of cassava starch and high protein flours, such as peanut, soy, or wheat. Non-grain breads have been made from cassava composite flours. About a 30:70 ratio of high-protein flour to cassava starch is required, and chemical modifiers, fat, and sometimes malt are essential to successful preparation of the baked product. It has heretofore been possible to use only composite flours, not cassava flour alone, to produce non-wheat products of risen structure, and the risen structure-type products have only been possible from composite flours when chemical modifiers and fat are also used. Until the present invention it was thought that the protein content of and the levels of diastatic enzymes in, cassava flour or starch were too low, and that cassava flour alone could not be used to produce baked products of risen structure.
The whole cassava flour of the prior art is prepared from the portion of the cassava tuber that remains after the thick peel and the woody portions of the tuber are discarded. The pulverized meal is sieved as the final step to flour production; these steps remove substantial amounts of fiber from the final flour product. This cassava flour does not have the properties of the instantly claimed flour and cannot be used successfully as a primary flour to prepare baked products and the like.
No investigator has been able to use more than a 30% substitution of the above whole cassava flour for wheat flour in preparation of baked products, and whole cassava flour is considered greatly inferior to cassava starch. Until the present invention, it was generally thought that the fiber content of cassava flour strongly interferes with formation of risen structure.
The general teachings of the art which have directed investigators completely away from developing the cassava flours and the uses of the instantly claimed invention are as follows:
1) The art teaches that the best cassava flour for baking is one which has a high starch level and in fact is a starch.
2) The art teaches that tubers with the highest possible starch content and lowest possible fiber content are preferred as sources for flour. The least desirable, to the point of being unusable are post mature tubers where starch levels have dropped and lignification (resulting in highest possible fiber content) has occurred.
3) The art also teaches against the use of the entire substance of the cassava tuber. Indeed prior art teachings concerning processing steps for production of cassava flour, involve selective removal and discarding of the most fibrous portions of the cassava tuber. In the instantly claimed invention, the flours from such lignified tubers produce a flour with the best properties.
When processing cassava tubers, the art teaches that the fibrous, woody ends of the cassava tubers are to be cut off and discarded, also the low starch inner layer of the peel is usually discarded. These teachings produce flours with reduced levels of protein and fiber in comparison to the instantly claimed flour.
Cassava has a thick peel composed of a thin outer cork layer (1/2-2% of total weight of the tuber) and a thick inner layer composed of the phelloderm and phloem (8-15% of total weight of the tuber). On average, 25% of the root is discarded as skin and trimmings. Therefore the amount of highly fibrous material removed from cassava in trimming and removing the fibrous woody ends is about 10-15% of the total weight of the tuber.
Although if the outer cork layer of the skin is included in the instantly claimed flour product, its presence will not alter the unexpected benefits of the instantly claimed invention, the presence of the thin cork layer in the flour will interfere with the taste and color of the flour, and removal of the thin cork layer is preferred.
Even assuming that the maximum amount, 2%, of the cork layer is removed, and allowing 5% for removal of blemishes and the like, a total of about 18% of the cassava tuber that is normally discarded as inner peel and woody ends, is incorporated into the instantly claimed invention. (This percentage can rise to about 50% when post mature, lignified tubers are used in flour production.) The inner part of the peel, is known to contain only about half of the amount of starch of the core of the root and therefore contains greatly increased amounts of fiber. The highly woody ends of the roots are even lower in starch and higher in fiber than the inner layer of the peel.
4) The art also teaches that flour finishing steps of the art select for high starch and low fiber content of the finished flour. The art teaches that in processing flour, bolting or otherwise sieving is performed to produce a finer flour. A flour processed by screening or the like can not contribute the part removed by screening to the finished flour, and therefore the entire, thinly peeled substance of the tuber is not utilized. Screening processes significantly reduce the fiber content of the finished flour.
Sieving a cassava flour will reduce both the fiber content and the protein content. When the most coarse fraction of a cassava flour and the finest fractions are compared, the coarse fraction contains about 3.5 times the amount of fiber of the finest fraction, and the coarse fractions are much higher in protein as well.
5) The art teaches strongly that in preparing baked products, no more than 30% of the wheat flour ingredient may be replaced by cassava and that to achieve these levels requires the addition of shortening or oils, chemical modifiers, and the like.
6) The art finally teaches that non-wheat baked products of risen structure can not be prepared from cassava flour alone, and that baked products prepared from cassava flour are possible only when prepared from composite flours (comprised for example of cassava flour and a high protein pressed seed flour), and other essential ingredients including chemical modifiers and shortening.
Other than the above mentioned uses of cassava flour as an ingredient in baked goods, there have been very few attempts to develop food products from cassava flour. Pasta products have been prepared from composite flours containing cassava flour. Cassava starch is commonly used as a minor ingredient in ice cream.
The cassava flour of the instantly claimed invention has properties that are opposite to these teachings. The best flour is not a starch but rather a whole flour containing increased amounts of plant fiber and other non-farinaceous materials than are previously encountered. Tubers with high fiber content are preferred sources for the flour. Preferred processing steps incorporate woody parts and inner peel into the flour. The best flour comminutes all fibrous material into the flour. Preferred flours for baking are fine in particle size. Baked products from 100% cassava flour are made, and no other flours, chemical modifiers and the like are needed other than water and a leavening agent.
In my early research on cassava, the cassava flour was made by a high speed impact method which produced a flour of wide particle-size distribution, with the fibrous portions of the tuber remaining in the larger particle sizes, and rendering the flour unsuitably heavy and gritty. When screened, (as is accepted practice in the art to obtain a fine flour) the large particles were removed (this amounted to about 1/4 of the flour product); this produced a lighter and less gritty flour, but one poorly suited for producing breads and other products where consistency and lightness are important. In addition it has been found that previous shreds had a high moisture content that made them susceptible to spoilage during dehydration and produced inferior products that spoiled easily.
I then developed a new process for preparing cassava flour which involved reducing moisture content, incorporating more fibrous and non-farinaceous material into the flour, and obtaining a more uniform particle size distribution in the flour. This flour had improved storage capability and provided products of palatable consistency. This flour, the flour of the instantly claimed invention, is previously not known. The properties of this flour are uniquely and suprisingly different from the previously existing flours. There would be no reason to suspect that the instantly claimed flour would have these properties. The new flour is suitable for use in baked and other products, and it was possible to develop new processes, different from conventions of the art, which made it possible to use the cassava flour of the instantly claimed invention to prepare products with properties and characteristics previously only obtainable from products containing wheat and other grains, legumes, eggs, milk, nuts and the like.
Malanga: Malanga represent one of the edible aroids of the family Araceae that includes taro, amorphophallus, tannia, yautia, eddo, cocoyam and many other species and varieties. They are widely consumed in Asia, Africa, Polynesia and Latin America, and they are almost exclusively eaten fresh by families who grow them. The term malanga, as used in this specification, is intended to include taro, amorphophallus, tannia, yautia, and the many other species and varieties.
There are few teachings of the art regarding any uses of edible aroids. The tubers are cooked and eaten, or the cooked tubers are pounded to a paste-like consistency and given to infants and the infirm. The paste is also used to make poi. The cooked tubers in a time-consuming process, are grated and combined with grated plantain or cassava. The mixture is stuffed with stew meat, and fried or wrapped in banana leaves and boiled in salted water. The final products are called pasteles or alcapurrias. Poi is dried and flaked to produce a product that can be rehydrated to produce an instant poi.
There are few references to malanga, taro, amorphophallus and other tubers of the family Araceae in the patent literature. U.S. Pat. No. 3,767,424 describes a method of separating starch from the tubers of Amorphophallus konjac, a tuber in the family Araceae. Starches from edible aroids produced by the above process and others are used commercially as thickening agents, in pharmaceutical products, and the like.
A very coarse flour (0.3 inch mesh) of tannia is the only whole flour of edible aroids known prior to the instantly claimed invention. The coarse flour was combined with water and rehydrated to form an edible food product whose properties are similar to those of the fresh tuber. This flour cannot be used according to the teachings of the instantly claimed invention to prepare products of risen structure and the like.
In the process for preparing the only flour known, the art teaches a process step of prolonged soaking. I find that the step of soaking in water greatly increases the water content of the tuber, prolongs the time period where conditions favor mold, and makes the drying materials highly susceptible to, and virtually unable to avoid, mold formation in the drying step. The instantly claimed invention teaches steps of minimizing soaking in water during peeling and during other process steps, immediate beginning of dehydration after shedding or otherwise comminuting, and achieving a dried product in the shortest possible time to avoid a sour taste in the dried product.
There is no teaching of the art regarding the use of malanga flour or the flour of other edible aroids in the preparation of baked products. Indeed, this use would not be possible with the only flour heretofore available.
The malanga flour of the instantly claimed invention is previously not known. The properties of this flour are uniquely and suprisingly different from the previously existing flours.
In my early research on malanga flour, I soaked the malanga tubers and then shredded them prior to dehydration. The soaking caused large portions of the drying shreds to spoil before becoming sufficiently dry and large amounts had to be discarded; the mold levels were unacceptably high in the dried product and palatability was poor. This problem was corrected by eliminating the step of soaking.
My first malanga flour product was prepared according to the conventions of the art. The flour contained a relatively wide particle-size distribution, with the fibrous portions of the tuber remaining in the larger particle sizes, and rendering the flour unsuitably heavy and gritty. When screened, (as is accepted practice in the art to obtain a fine flour) the large particles were removed; this produced a lighter and less gritty flour, but one poorly suited for producing breads and other products where consistency and lightness are important.
I then developed a new process for preparing malanga flour which involved reducing moisture content, incorporating more fibrous and non-farinaceous material into the flour, and obtaining a more uniform particle size distribution in the flour. This flour had improved storage capability and provided products of palatable consistency. This flour, the flour of the instantly claimed invention, is suitable for use in baked and other products, and it was possible to develop new processes, different from conventions of the art, which made it possible to use the malanga flour of the instantly claimed invention to prepare products with properties and characteristics previously only obtainable from products containing wheat and other grains, legumes, eggs, milk, nuts and the like.
Yam: There are no references to yam flours or products containing yams in the U.S. patent literature. Prior to the instantly claimed invention, flours of yam were known, however during processing from raw vegetable to dried flour, a powerfully strong and often strongly bitter taste was introduced. There is no mention in the literature of any interest in reducing the strong or bitter taste, nor of any investigations in this area. Rather there seems to be a matter of fact acceptance of this property of the flour. Emphasis is placed on helping consumers become accustomed to the taste, and on a search for a less bitter yam variety.
Prior to the instantly claimed invention, attempts were made by others to use the strong flavored or bitter flours of the art them in baked products. Such yam flours have been used in pancakes, cupcakes, rolls, and breads. Yam flour was substituted for 50% of the wheat flour in products of pancakes, cupcakes, and rolls, for 20% of the wheat flour in products of bread, and in one batch of cupcakes yam flour was substituted for 100% of the wheat flour. All such products included other ingredients such as milk, eggs, sugar, and the like. Such other ingredients were required to mask the disagreeable taste of the flour, as well as to contribute to needed texture and structure.
Other than the above mentioned uses of yam flour as an ingredient in baked goods, there are no known attempts to develop food products from yam flour.
There are no teachings regarding the use of such yam flour to prepare milk substitutes, egg substitutes, substitutes for nut, butters, or flour substitutes other than baked products of risen structure. There is further no teaching to suggest that such uses are possible.
To develop satisfactory uses for yam, processes for using the flour had to be developed, but these could not be used to prepare good tasting products unless a bland, non-bitter flour could be prepared.
As a first step in developing a non-bitter flour, the applicant began by observing that the traditional ways for cooking fresh yams involve relatively gentle, moist heat cooking techniques. When prepared in this manner, the yams are very bland and pleasant tasting; the taste and texture are difficult to distinguish from similarly cooked fresh potatoes. When high heat methods of cooking, particularly with oil, such as in frying, are used, the yam becomes strongly flavored or strongly bitter. When yams are baked, or air dried with heat (even low heat), they become strongly, disagreeably, bitter.
In processes of producing yam flour, the applicant has found that art recognized techniques of dehydration, such as air drying with heat or sun drying, resulted in the introduction of a strong flavor or bitter taste. Furthermore processes of comminuting dried yam to produce flour also caused the flour to turn strongly flavored or bitter.
As is known in the art, when yams are cooked prior to sun drying or air drying with heat, the cooked, dried yam shreds, pieces, or chips become less bitter than those of uncooked yam, but the bitter taste is still present. The cooked, dried shreds and the like are very hard and require harsh grinding conditions, e.g., longer grinding times and greater force applied, than is required for uncooked shreds. The applicant has found that the more harsh grinding conditions necessary for cooked, dried yam shreds causes the strong bitter taste to reappear. Therefore both cooked and uncooked dried yam flours of the are tend to be strong flavored and bitter.
The applicant has found that a good tasting, not bitter yam flour could be prepared when low temperature drying and grinding conditions were used to produce cooked and uncooked flours, and that these flours could then be used in baked products.
To produce a flour that could best be used in preparation of baked products and the like, it was further found that retaining as much of the fiber in the flour as possible improved the characteristics. The new, non-bitter yam flour, otherwise produced by the conventions of the art could not be used to prepare the desired products In my first attempts to prepare yam flour, the flour produced had a relatively wide particle-size distribution, with the fibrous portions of the tuber remaining in the larger particle sizes, and rendering the flour unsuitably heavy and gritty. When screened, (as is accepted practice in the art to obtain a fine flour) the large particles were removed; this produced a lighter and less gritty flour, but one poorly suited for producing breads and other products where consistency and lightness are important. In addition it has been found that previous shreds had a high moisture content that made them susceptible to spoilage during dehydration and produced inferior products that spoiled easily.
I then developed a new process for preparing yam flour which involved reducing moisture content, incorporating more fibrous and non-farinaceous material into the flour, and obtaining a more uniform particle size distribution in the flour. This flour had improved storage capability and provided products of palatable consistency. This flour, the flour of the instantly claimed invention, is suitable for use in baked and other products, and it was possible to develop new processes, different from conventions of the art, which made it possible to use the new yam flour to prepare products with properties and characteristics previously only obtainable from products containing wheat and other grains, legumes, eggs, milk, nuts and the like.
By these methods, a flour was produced that not only eliminated the problem of strong flavor or bitter taste, but which could also be used in novel processes to produce good tasting baked and other products wherein yam flour was not only the sole flour, but also was essentially the sole ingredient. Yam flour alone can be used to produce good tasting products, and added ingredients such as fat, eggs, milk, chemical modifiers and the like are not essential to preparation of acceptable products; although their use is not precluded.
A yam flour without a strong flavor or bitter taste and with the properties described above is unknown prior to the instantly claimed invention. No yam flour in the prior art has the properties of the instantly claimed invention; no yam flour in the prior art can be used in the ways described for the instantly claimed invention.
The general teachings of the art which have directed investigators completely away from developing the yam flours and the uses of the instantly claimed invention are as follows:
1) The art teaches that yam flours are disagreeable and strongly bitter in taste. This flavor carries into the finished, baked products rendering them strongly flavored or bitter or requiring the use of other ingredients to mask the taste.
2) The art also teaches that to successfully prepare baked products requires inclusion of other ingredients such as milk, sugar, eggs, chemical modifiers and the like.
3) The art finally teaches that even with the above ingredients, breads with satisfactory properties of 20-40% and higher yam flour content cannot be made, and that most other products can not be made at levels higher than 50%.
The yam flour of the instantly claimed invention has properties that are opposite to these teachings. The flour is not strongly flavored or bitter in taste. Baked products from 100% yam flour can be made, and no other flours, chemical modifiers, other ingredients, and the like are needed other than water and a leavening agent to make such baked products.
The yam flour of the instantly claimed invention is previously not known. The properties of this flour are uniquely and suprisingly different from the previously existing flours. There would be no reason to suspect that the instantly claimed flour would have these properties.
Amaranth: Amaranth flour products known prior to the instantly claimed invention are coarse, heavy, and grainy, the consistency of corn meal-type products. When used to produce products in which the heavy flour was the primary ingredient other than water or oil, the products were inferior in consistency, texture and palatability.
Prior to the instantly claimed invention, the following flours of amaranth are known: a coarse whole flour of amaranth, a fine sieved fraction of the coarse whole amaranth flour, and amaranth flours formed by pulverizing popped, toasted or parched amaranth. None of these flours have the properties of the instantly claimed invention; none can be used in the ways described for the instantly claimed invention.
1) Whole raw amaranth flour is a coarse meal of amaranth seeds. Amaranth seeds are very small, ranging from 0.9-1.5 mm in diameter, and they are very hard. The whole amaranth flours known in the art that are milled from raw amaranth are coarse, grainy and heavy, with a consistency similar to that of corn meal.
The finest whole amaranth flour previously known to the applicant prior to the instantly claimed invention is a flour in which amaranth seeds were milled and then sifted through a 40-mesh screen (aperture 0.425 mm). This particle size is very coarse for amaranth grains; a particle with a diameter one-third that of an unmilled seed would pass through this aperture. Such a flour is gritty and heavy, with the consistency of heavy corn meal. This flour is also sieved and therefore has different properties from truely whole amaranth flour.
When prior investigators used such amaranth flour in the preparation of bread products, the investigators were able to use such amaranth flour for up to 20% of the wheat flour in wheat-containing products without too great of an effect on overall properties; however, other ingredients including yeast, lard, sugar, malt, milk various emulsifiers, flavorings and the like were included in the products. No products were prepared without the added ingredients. Such amaranth flour can be used for as much as 50% of the wheat flour ingredient in cookies, pizza doughs, and short pasta, and as much as 5% in long pasta. These levels represent the upper limits of the teachings of the art regarding uses and possible substitutions of sifted, coarse, raw amaranth flours for wheat flours.
2) Fine, raw amaranth flour is the sifted, coarse raw amaranth flour described above that is further milled to a finer flour by bolting and sieving techniques. From a typical milling process, the following fractions are generally obtained: 52.6% `bran`, 20.1% broken grains, 16.2% coarse flour and 10.4% fine flour.
Other investigators have shown that fiber and protein contents of various flour fractions are significantly different. When the coarse amaranth meal is passed through an 80 mesh screen, the resulting flour fraction contains about 24-36% of the protein. A more coarse fraction, obtained by passing the coarse meal through a 60 mesh screen contained only 8-9% protein. Still finer amaranth flours can be made by passing the flour through a 100 mesh screen.
Fine amaranth flours comprise from about 10 to 30% of the original material of the seed. The finer the flour fraction, the greater the difference there is in protein content, fiber content and the like in comparison to the unmilled seed.
In prior attempts by other investigators to use amaranth flours in combination with wheat and other ingredients to prepare baked products, the more coarse fraction (40-60 mesh) was the preferred fraction, requiring reduced mixing times, and producing products with improved sensory properties and larger volumes. There is no suggestion in the teachings of the art that would direct one of ordinary skill in the art to explore the properties of finer, non-fractionated flours.
3) Popped, toasted, parched amaranth flours are produced by first popping, toasting or parching amaranth seeds, and then pulverizing to form a flour. These flours are prepared because amaranth is easier to mill after seeds have been treated with high heat, and thus finer flours can be prepared more easily. These flours are also subjected to the common particle size separations.
Although these flours may be easier to mill, the heat treatment processes result in changes in the structure of the seeds and resulting flour. These flours therefore are not well suited to the products and processes of the instantly claimed invention.
The general teachings of the art which have directed investigators completely away from developing the amaranth flours and the uses of the instantly claimed invention are as follows:
1) The art teaches that the best amaranth flour for baking is the coarse fraction sieved form the coarse whole amaranth flour.
2) The art teaches that in preparing baked products of risen structure, no more than 20% of the wheat flour ingredient may be replaced by whole amaranth. The art also teaches that amounts of amaranth flour varying from 5-50% may be substituted for wheat flours in selected products such as cookies, pizza dough, pastas, and the like.
3) The art finally teaches that to prepare breads and the like from amaranth composite flours requires as essential ingredients in addition to amaranth and wheat flours: sugar, fat, milk, malt, chemical modifiers, and the like.
In working with amaranth flours, I began by separating coarse and fine flour fractions from the coarse whole amaranth flour as described in the art. When the various fractions were used as the sole flour in baked products, milk substitutes, and the like, heavy, crumbly, and largely undesirable products were produced. To achieve the texture, cohesiveness, and desired risen structure of products produced from an amaranth flour, a fine, whole amaranth flour was needed.
Such a flour, the flour of the instantly claimed invention, was milled in a stone mill set at the finest setting possible and the meal was passed in small amounts through the mill, with repetitions as necessary to produce a finely comminuted flour. However the flour can be prepared by any techniques necessary to achieve the desired result, provided that mechanical flour fraction separation processes are minimized.
With this flour the applicant was able to develop processes appropriate to the production of many previously unavailable products. The new amaranth flour, together with only water, oil, and leavening, is used to make breads, cookies, pastas, and the like. There are no teachings regarding the use of amaranth flour to prepare milk substitutes, egg substitutes, or substitutes for nut butters. There is no teaching to suggest that such uses are possible.
Based on the information available and based on the teachings of the art, an investigator with average skill in the art would have no reason to suspect the surprising improvements in quality and characteristics of the instantly claimed amaranth flour.
It has now been found that flours having finer, more uniform particle size can be prepared that produce greatly improved products including those where amaranth flour is the primary or only ingredient other than water and oil.
Lotus: Lotus was investigated as a source for new food products. Lotus is an aquatic plant which is virtually completely edible. The lotus produces tuberous roots which are commonly eaten in the Orient as side dishes and in combination with many other ingredients. Lotus starch exists in commerce with typical uses of starch. Prior to the present invention a whole flour of lotus was unknown.
In my early research on developing lotus flour, the lotus flour was made by a high speed impact method which produced a flour of wide particle-size distribution, with the fibrous portions of the tuber remaining in the larger particle sizes, and rendering the flour unsuitably heavy and gritty. When screened, (as is accepted practice in the art to obtain a fine flour) the large particles were removed; this produced a lighter and less gritty flour, but one poorly suited for producing breads and other products where consistency and lightness are important.
I then developed a new process for preparing lotus flour which involved incorporating more fibrous and non-farinaceous material into the flour, and obtaining a more uniform particle size distribution in the flour. This flour, the flour of the instantly claimed invention, is suitable for use in baked and other products, and it was possible to develop new processes, different from conventions of the art, for using the lotus flour of the instantly claimed invention to prepare products with properties and characteristics previously only obtainable from products containing wheat and other grains, legumes, eggs, milk, nuts and the like.